import adapter.FeedListAdapter;
import app.AppController;
import data.FeedItem;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.widget.SwipeRefreshLayout;
import android.view.Window;
import android.view.WindowManager;
import android.widget.ListView;
import com.android.volley.Cache;
import com.android.volley.Cache.Entry;
import com.android.volley.Request.Method;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.VolleyLog;
import com.android.volley.toolbox.JsonObjectRequest;
public class MainActivity extends Activity {
private static final String TAG = MainActivity.class.getSimpleName();
private ListView listView;
private FeedListAdapter listAdapter;
private List<FeedItem> feedItems;
private String URL_FEED = "http://myozawoo.esy.es/data.php";
private String URL_FEED2 = "http://api.androidhive.info/feed/feed.json";
private SwipeRefreshLayout swipeContainer;
// String page = getIntent().getExtras().getString("page");
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 0);
setContentView(R.layout.activity_main);
// String page = getIntent().getExtras().getString("page");
swipeContainer = (SwipeRefreshLayout) findViewById(R.id.swipeContainer);
swipeContainer.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
listAdapter.notifyDataSetChanged();
}
});
listView = (ListView) findViewById(R.id.list);
feedItems = new ArrayList<FeedItem>();
listAdapter = new FeedListAdapter(this, feedItems);
listView.setAdapter(listAdapter);
// These two lines not needed,
// just to get the look of facebook (changing background color & hiding the icon)
// getActionBar().setBackgroundDrawable(new ColorDrawable(Color.parseColor("#3b5998")));
// getActionBar().setIcon(
// new ColorDrawable(getResources().getColor(android.R.color.transparent)));
// We first check for cached request
// Cache cache = AppController.getInstance().getRequestQueue().getCache();
// Page One
String page = getIntent().getExtras().getString("page");
if(page.equals("1")) {
Cache cache = AppController.getInstance().getRequestQueue().getCache();
Entry entry = cache.get(URL_FEED);
if (entry != null) {
// fetch the data from cache
try {
String data = new String(entry.data, "UTF-8");
try {
parseJsonFeed(new JSONObject(data));
} catch (JSONException e) {
e.printStackTrace();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
} else {
// making fresh volley request and getting json
JsonObjectRequest jsonReq = new JsonObjectRequest(Method.GET,
URL_FEED, null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
VolleyLog.d(TAG, "Response: " + response.toString());
if (response != null) {
parseJsonFeed(response);
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
}
});
// Adding request to volley request queue
AppController.getInstance().addToRequestQueue(jsonReq);
}
}
//Page Two
else if (page.equals("2")) {
Cache cache = AppController.getInstance().getRequestQueue().getCache();
Entry entry = cache.get(URL_FEED2);
if (entry != null) {
// fetch the data from cache
try {
String data = new String(entry.data, "UTF-8");
try {
parseJsonFeed(new JSONObject(data));
} catch (JSONException e) {
e.printStackTrace();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
} else {
// making fresh volley request and getting json
JsonObjectRequest jsonReq = new JsonObjectRequest(Method.GET,
URL_FEED2, null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
VolleyLog.d(TAG, "Response: " + response.toString());
if (response != null) {
parseJsonFeed(response);
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
}
});
// Adding request to volley request queue
AppController.getInstance().addToRequestQueue(jsonReq);
}
}
// Other Four Pages
else {
Cache cache = AppController.getInstance().getRequestQueue().getCache();
Entry entry = cache.get(URL_FEED);
if (entry != null) {
// fetch the data from cache
try {
String data = new String(entry.data, "UTF-8");
try {
parseJsonFeed(new JSONObject(data));
} catch (JSONException e) {
e.printStackTrace();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
} else {
// making fresh volley request and getting json
JsonObjectRequest jsonReq = new JsonObjectRequest(Method.GET,
URL_FEED, null, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
VolleyLog.d(TAG, "Response: " + response.toString());
if (response != null) {
parseJsonFeed(response);
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
}
});
// Adding request to volley request queue
AppController.getInstance().addToRequestQueue(jsonReq);
}
}
swipeContainer.setColorSchemeColors(android.R.color.holo_blue_bright,
android.R.color.holo_green_light,
android.R.color.holo_orange_light,
android.R.color.holo_red_light);
}
/**
* Parsing json reponse and passing the data to feed view list adapter
* */
public void parseJsonFeed(JSONObject response) {
try {
// String page = getIntent().getExtras().getString("page");
// if (page.equals("1"))
JSONArray feedArray = response.getJSONArray("feed");
for (int i = 0; i < feedArray.length(); i++) {
JSONObject feedObj = (JSONObject) feedArray.get(i);
final FeedItem item = new FeedItem();
item.setId(feedObj.getInt("id"));
item.setName(feedObj.getString("name"));
// Image might be null sometimes
String image = feedObj.isNull("image") ? null : feedObj
.getString("image");
item.setImge(image);
item.setStatus(feedObj.getString("status"));
item.setProfilePic(feedObj.getString("profilePic"));
item.setTimeStamp(feedObj.getString("timeStamp"));
// url might be null sometimes
String feedUrl = feedObj.isNull("url") ? null : feedObj
.getString("url");
item.setUrl(feedUrl);
feedItems.add(item);
}
// notify data changes to list adapater
listAdapter.notifyDataSetChanged();
} catch (JSONException e) {
e.printStackTrace();
}
swipeContainer.setRefreshing(false);
}
}
我想刷新。如果刷新，我可以获得更多数据。我不知道如何获取新数据。谁想帮帮我？我需要帮助。我使用了刷卡刷新布局。我不知道如何连接parseJSON（）{}。抱歉我的英语不好！
答案 0 :(得分：1)
将滚动侦听器添加到listview以检查列表视图项的位置，并启用“刷卡刷新” 只有它在顶部。 将以下代码添加到onCreate（）
listView.setOnScrollListener(new OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
boolean enable = false;
if(listView != null && listView.getChildCount() > 0){
// check if the first item of the list is visible
boolean firstItemVisible = listView.getFirstVisiblePosition() == 0;
// check if the top of the first item is visible
boolean topOfFirstItemVisible = listView.getChildAt(0).getTop() == 0;
// enabling or disabling the refresh layout
enable = firstItemVisible && topOfFirstItemVisible;
}
swipeRefreshLayout.setEnabled(enable);
}});